Indicating apparatus

ABSTRACT

An indicating apparatus for providing a visual linear output signal related to a measure variable in response to a voltage signal received from a sensor which measure the variable and provides an output voltage signal analogous thereto.

United States Patent [72] Inventors Edward H. Moore Avon;

Milton A. Aron, Newington, both of Conn. [21] AppL- No. 828,563

[22] Filed May 28,1969 [45] Patented Oct. 19,1971

3,3 35,414 3,443,438 5/1969 Martin et a1. 3,519,849 7/1970Tyler............

[73] Assignee The Gems Company, Inc.

Farmlngton, Conn.

Primary Examiner-John W. Caldwell Assistant Examiner-Robert J. Mooney 5INDICATING APPARATUS Attorney-McCormick, Paulding & Huber 10 Claims, 6Drawing Figs.

340/212, ABSTRACT; An indicating apparatus for providing a visual340/378 R, 317/101 R, 340/366 d to a measure variable in re lineai'output signal relate sponse easure the [51] Int. Cl...... H02b l/04, toa voltage signal received from a sensor which m 1102b 9/00 variable andprovides an output voltage signal analogous [50] Field of 340/212,thereto.

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PATENTEDnm 19 Ian SHEET 1 BF 2 S. S a R VI mm M WOW 1 O M DA l on MW Fmu J vm u N B mm INDICATING APPARATUS BACKGROUND OF THE INVENTION Thisinvention relates to improved indicating apparatus and deals moreparticularly withapparatus for providing continuous remote indication ofa measured variable as, for example, the level of liquid in a tank orthe like.

The general aim of the present invention is to provide an improvedapparatus of the aforedescribed type for providing a visual graphicoutput signal analogous to a measured variable. A further aim of theinvention is to provide a durable compact indicating apparatus which maybe readily adjusted to generate a visual linear output signal related toa measured variable in response to a nonlinear signal received from asensor which measures the variable.

The apparatus of the present invention may be used with any sensor ortransmitter capable of producing an output voltage signal the value ofwhich is related to a measured variable as, for example, pressure ortemperature. It has proven particularly suitable, however, for providingcontinuous remote indication of the level of a liquid in a tank or thelike. The apparatus may, for example, be readily adjusted to provide agraphic indication directly proportional to the quantity of liquid in anirregularly shaped tank where the measured variable is the level ofliquid in the tank. The present apparatus is also particularly suitedfor applications where remote simultaneous monitoring of a plurality ofmeasured variables is required as, for example, in a ship tanklevel-gauging system or the like.

SUMMARY OF THE INVENTION In accordance with the present invention anindicating apparatus is provided for producing a visual output signal ofa bar graph type in response to an output voltage signal received from atransmitter and analogous to the measured variable.

- The apparatus includes means for adjusting the visual output signalresponse relative to the output voltage signal received from thetransmitter.

' BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF PREFERREDEMBODIMENT Referring now to the drawings and particularly to FIG. 1,thereof, a liquid-level-indicating or tank-gauging system is shown whichincludes an indicating device or receiver embodying the presentinvention and designated generally by the numeral and a transmitter,indicated generally at 12, electrically connected to the receiver forproviding an output voltage signal related to the level of a liquid 14contained in a tank 16. The receiver supports a plurality of lamps 18,18, each lamp being connected to a respectively associated lamp circuitindicated generally at' 20. Each lamp circuit 20 is arranged to respondto a predetermined output voltage signal from the transmitter 12 toswitch an associated lamp 18 from a deenergized to an energized statewhen the output voltage signal exceeds such predetermined level and froman energized to a deenergized state when the output voltage signal isless than the predetermined level. The lamp circuits 20, 20 are eachresponsive to a difierent predetermined output voltage level. In theschematic circuit diagram of FIG. 1, three lamp circuits 20, 20areshown, however, any number of lamp circuits may be provided, thenumber of circuits being determined by the desired indicating range orsensitivity of the apparatus. The lamps l8, 18 are arranged inlongitudinal series and preferably operate in longitudinal sequence toprovide a visual lineal output signal to indicate the level of theliquid 14 in the manner of a bar graph as will be hereinafter evident.

Further considering the FIG. 1, the transmitter 12 is schematicallyillustrated as a potentiometer connected to a DC output source by a line21 and a ground line 22. The potentiometer 12 includes a resistor 24 anda wiper 26 connected to a signal voltage line 28 and arranged to movewith a float 29 and relative to the resistor 24 in response to change inthe level of the liquid 14. The apparatus also includes a slave meter 30located near the tank 16 and connected in series with a resistor 32between the ground line 22 and the signal voltage line 28 to provideindication of the approximate level of the liquid 14. A filter for theoutput signal voltage from the transmitter 12 is provided by a capacitor34 and a resistor 36 connected in parallel across the lines 22 and 28.The lines 22 and 28 additionally connect the transmitter 12 to thereceiver 10.

Considering now the electrical circuitry associated with the receiver10, as shown in FIG. 1, a typical lamp circuit 20 includes afield-effect transistor 38, a PNP transistor 40, and an NPN transistor42 which cooperate to switch an associated lamp 18 between an energizedand deenergized state in response to changes in the signal voltageappearing on the line 28. Each lamp circuit is connected to twodifferent voltage outputs of a DC power source by the lines 44 and 46.The field-effect transistor 38 has a control or gate terminal 48connected to a line 50 which is, in turn, connected to the signalvoltage line 28 at a junction 52. The source terminal of thefield-effect transistor 38 is connected to the supply line 44 through avariable resistor 56 and a resistor 58. Another resistor 60 is connectedbetween the source terminal and ground. The transistor 40 has itsemitter terminal connected to the supply line 44 and its base terminalconnected to the drain terminal of the field-effect transistor 38. Thecollector terminal of the transistor 40 is connected to ground throughresistors 62 and 64. The base terminal of the transistor 42 is connectedto the junction 66 between the resistors 62 and 64. Thecollector-emitter circuit of the transistor 42 forms a grounding circuitfor the lamp 18 which is connected to the DC power supply line 46through an adjustable voltage varying device 67 which controls thebrightness of all of the lamps.

The source-drain circuit of the field-effect transistor 38 forms acontrol circuit for the biasing of the transistor 40, and theemitter-collector circuit of the latter transistor forms a controlcircuit for the biasing of the transistor 42. When the field-effecttransistor 38 has its source drain circuit turned on or biased to aconducting state the transistors 40 and 42 will also be turned on orswitched to a conducting state with respect to their respectiveernitter-collector circuits so that power will flow through the lamp 18.

It will be noted that the gate or control terminals 48, 48 of all of thefield-effect transistors 38, 38 are connected in common at the junction52 so as to simultaneously receive the signal voltage from thetransmitter 12. Due to the high-impedance characteristics of thefield-effect transistors no substantial voltage variation occurs at thejunction 52 when the various lamps 18, 18 are switched between theirenergized and deenergized states. The variable resistors 56, 56 areadjusted so that each lamp circuit 20 responds to a differentpredetermined output voltage from the other of the lamp circuits.Preferably, the lamp circuits 20, 20 are adjusted by means of theirresistors 56, 56, so that the lamps 18, 18 switch on and off inlongitudinal sequence as the level of the liquid 14 increases ordecreases to provide a direct graphic indication of the level of liquidin the tank 16. If desired, the receiver may be calibrated to indicateliquid quantity.

In some apparatus installations it may be desirable to provide a timedelay device (not shown) in the electrical circuit so that the variouslamp circuits 20, 20 are not immediately responsive to changes intransmitter output voltage. Such an arrangement is particularlydesirable where the liquid to be indicated may be in motion, as aboardship, and serves to stabilize the graphic output of the receiver.

Considering now the construction of the receiver in more detail, andreferring to FIGS. 2-6, the lamps l8, 18 used in practicing theinvention are of conventional type, and each has a base 70 whichincludes a cylindrical portion or terminal 72 and another terminal 74projecting from one end of the cylindrical portion and insulatedtherefrom. A translucent envelope 75 which contains a lamp filamentextends axially from the other end of the cylindrical portion 72.Important features of the invention reside in the construction of thereceiver and the matter in which the lamp and lamp circuit elements aresupported and arranged relative thereto. As oriented in the drawings,the receiver generally comprises a plurality of strips of materialarranged in adjacent side-by-side relation and includes a verticallyelongated divider strip 76 preferably made from durable opaque materialsuch as aluminum. A vertical series of forwardly opening lampcompartments 78, 78 are formed in the divider strip 76 and separatedfrom one another by a plurality of generally horizontal partitions 80,80. The lamps may be arranged to extend into the lamp compartments fromeither or both sides of the divider strip 76, but preferably as shownthe receiver 10 includes two groups of opposing lamps l8, 18 arranged inalternate series. One group of lamps extend into one group of lampcompartments 78, 78 from one side of the divider strip and the othergroup of lamps extend into another respectively associated andalternately staggered group of compartments from the opposite side ofthe strip. This arrangement permits the lamps to be supported in thereceiver 10 in relatively closely spaced relation to each other. Anelectrically conductive strip 84 is positioned adjacent each side of thedivider strip 76 and extends vertically along at least the forwardmarginal portion thereof. The strips 84, 84 are preferably made from anelastomeric material such as electrically conductive rubber forelectrical connection with the various lamp circuits and each strip hasa vertical series of cylindrical openings 86, 86 formed therein. Eachopening is aligned with a respectively associated lamp compartment 78and has a diameter slightly smaller than the diameter of an associatedlamp terminal 72 to snugly receive the latter terminal and establishelectrical contact therewith. In the illustrated embodiment, a strip ofinsulating material 88 is positioned between each conductive strip 84and an associated side of the divider 76.

The various circuit elements which comprise the lamp circuits 20, 20 arealso preferably mounted, as shown, on the receiver 10. For this reason,an insulating strip or printed circuit board 90 respectively overlayseach conductive strip 84. A plurality of circuit lines (not shown)imprinted on the inner surface of each circuit board 90 form portions ofthe lamp circuits 20, 20. A vertical series of cylindrical openings 92,92 are formed in each circuit board 90, each opening 92 being in generalcoaxial alignment with an associated opening 86. Each opening 92 issomewhat larger than its associated opening 86 to permit a lamp 18 topass freely therethrough.

A vertically spaced series of electrical contacts 94, 94 mounted on eachcircuit board 90 establish electrical contact with the lamp terminals74, 74. Each contact 94 is electrically connected to an associated lampcircuit 20 and is pivotally mounted so that it may be swiveled to aposition out of engagement with an associated terminal 74 to facilitatelamp removal and replacement. in FIG. 3, the lowermost contact 94 isshown in broken lines as pivoted to such a position of disengagement.

Each of the transistors and resistors which comprise the elements of thevarious lamp circuits 20, 20 are mounted on the outer side of theassociated circuit board 90 and are electrically connected to theimprinted circuits on the inner side of the board. It should be notedthat each variable resistor 56 is provided with an adjustment screw 96for varying the resistance thereof which is readily accessible from therear of the receiver 10.

In service, the receiver 10 may be mounted on a panel such as indicatedat 98 by fasteners 100, 100. A translucent plate 102, received in anopening in the panel 98, overlies the front surface of the divider strip76, so that light from the lamps 18, 18 is visible therethrough, and isretained in assembly by a frame 104 and a gasket 106, as best shown inFIG. 3.

We claim:

1. An indicating apparatus for providing a visual lineal output signalrelated to a measured variable and for use with a transmitter whichproduces an output voltage signal the value of which is analogous to themeasured variable, said apparatus comprising an elongated dividerdefining a longitudinal series of lamp compartments, each compartmentbeing separated from the next successive compartment in said series by agenerally transversely extending partition, an electrically conductivestrip extending along one side of said divider and having a longitudinalseries of openings therein, each of said openings aligned with arespective one of said compartments, a longitudinal series of lamps,each of said lamps having a translucent envelope received in arespective one of said compartments and including a base received in arespective one of said openings, said base including two spaced-apartterminal portions, one of said terminal portions electrically contactingsaid conductive strip, an insulating strip extending along said oneside, and a longitudinal series of contacts mounted on said insulatingstrip, each of said contacts engaging the other of said terminalportions of a respective one of said lamps, and a plurality of lampcircuits, each of said lamp circuits being associated with one of saidlamps and including a control terminal and means for switching said onelamp from a deenergized to an energized state when the voltage on saidcontrol terminal exceeds a predetermined level and from an energized toa deenergized state when the voltage on said control terminal is lessthan said predetermined level, each of said lamp circuits beingresponsive to a different predetermined voltage level than the other ofsaid lamp circuits, said lamps being arranged to respond in longitudinalsequence to changes in said voltage level.

2. An indicating apparatus as set forth in claim 1 wherein each of saidlamp circuits includes means for adjusting said predetermined voltage.

3. An indicating apparatus as set forth in claim 2 wherein saidswitching means includes a field-effect transistor, said controlterminal comprises the gate terminal of said transistor and saidadjusting means comprise means for varying the volt age on the sourceterminal of said field-effect transistor.

4. An indicating apparatus as set forth in claim 1 wherein said lampsinclude two groups of alternately arranged lamps, said series ofcompartments include two groups of alternately arranged compartmentseach of said openings along said one side aligned with a respective oneof said compartments in one of said groups and receiving the base of anassociated one of the lamps in one of said groups of lamps, anotherelectrically conductive strip extending along the other side of saiddivider and having another longitudinal series of openings therein, eachof said openings in said other series aligned with a respective one ofsaid compartments in the other of said groups and receiving the base ofan associated one of said lamps in the other of said groups, anotherinsulating strip, extending along said other side and anotherlongitudinal series of contacts mounted on said other insulating strip,each of said contacts in said other series engaging said other terminalportion of a respective one of said lamps in said other group.

5. An indicating apparatus as set forth in claim 1 wherein saidinsulating strip extends some distance rearwardly of said openings andthe elements comprising each of said lamp circuits are mounted on saidinsulated strip.

6. An indicating apparatus as set forth in claim 5 wherein saidinsulated strip is a printed circuit board comprising a portion of eachof said lamp circuits.

7. An indicating apparatus as set forth in claim 1 wherein saidconductive strip comprises a piece of electrically conductiveelastomeric material, and each of said openings before receiving thebase of an associated one of said lamps is slightly smaller than saidbase of said one lamp.

8. An indicating apparatus as set forth in claim 1 wherein each of saidcompartments opens forwardly and including a translucent plate adjacentthe forward portion of said divider and covering said forwardly openingcompartments.

9. An indicating apparatus as set forth in claim 1 wherein each of saidcontacts is mounted on said insulating strip for pivotal movementrelative thereto into and out of engagement with said other terminalportion of an associated one of said lamps, said one lamp beingremovable from said apparatus when the contact associated therewith ispivoted to a position out of engagement with said other terminal portionthereof.

10. in indicating apparatus for providing a visual lineal output signalrelated to a measured variable and for use with a transmitter whichproduces an output signal the value of which is analogous to themeasured variable, said apparatus comprising an elongated dividerdefining a longitudinal series of forwardly opening lamp compartments,each compartment in said series being separated from the next successivecompartment in said series by a generally transversely disposedpartition, a strip of electrically conductive elastomeric materialpositioned generally adjacent and extending along one side of saiddivider and having a longitudinal series of openings therein, each ofsaid openings aligned with a respective one of said compartments, alongitudinal series of lamps, each of said lamps having a translucentenvelope received in a respective one of said compartments and includinga base received in a respective one of said openings, said baseincluding two terminal portions, one of said terminal portionselectrically contacting said electrically conductive strip, alongitudinally extending insulating strip overlying an associatedportion of said electrically conductive strip and extending rearwardlyfor some distance beyond said openings, a longitudinal series ofcontacts pivotally mounted on said insulating strip, each of saidcontacts being pivotally movable into and out of engagement with theother of said terminal portions of a respectively associated one of saidlamps, said one lamp being removable from said apparatus when thecontact associated therewith is pivoted to a position out of engagementwith said other terminal portion thereof, a plurality of lamp circuits,each of said lamp circuits being associated with one of said lamps andincluding a plurality of circuit elements mounted on said insulatingstrip, each of said circuits having a portion thereof printed on saidinsulating strip and including a control terminal and means forswitching said one lamp from a deenergized to an energized state whenthe voltage on said control terminal exceeds a predetermined level andfrom an energized to a deenergized state when the voltage on saidcontrol terminal is less that said predetermined level, each of saidlamp circuits being responsive to a difl'er'ent predetermined voltagelevel than the other of said lamp circuits, said lamp circuits beingarranged to respond in longitudinal sequence to changes in said voltagelevel, each of said lamp circuits including means for adjusting saidpredetermined voltage, and a translucent plate adjacent the forwardportion of said divider and covering said forwardly openingcompartments. circuits each of said lamp circuits being associated withone of said lamps and including a plurality of circuit elements mountedon said insulating strip, each of said circuits having a portion thereofprinted on said insulating strip and including a control terminal andmeans for switching said one lamp from a deenergized to an energziedstate when the volatge on said control terminal exceeds a predeterminedlevel and from an energized to a deenergized tate when the voltage onsaid control terminal, is less that said predetennined level, each ofsaid lamp circuits being responsive to a different predetermined voltagelevel than the other of said lamp circuits, said lamp circuits beingarranged to respond in longitudinal sequence to changes in said voltagelevel each of said lamp circuits including means for ad usting saidpredetermined voltage, and a translucent plate adjacent the forwardportion of said divider and ocverin g said forwardly openingcompartments.

Patent No.

Inventor(s) 3,614,759 Dated October 19, 1971 Edward H. Moore, Milton A.Aron It is certified that error appears in the above-identified patent:

and that said Letters Patent are hereby corrected as shown below:

EDWARD M.FLETCHER, JR. Attesting Officer Abstract, line 3, "measure"should read -measures-.

Col. 3, line 16, "lamp" (first occurrence) should read --1amps--.

Col. 3, line 18, "drawings" should read -drawing-.

Col. 3, line 72, after "associated" insert printed.

Claim 10; delete lines 22-38 beginning and ending as follows: "circuits,each...forwardly opening compartments."

Signed and sealed this 27th day of June 1 972.

(SEAL) Attest:

ROBERT GO'I'TSCHALK Commissioner of Patents

1. An indicating apparatus for providing a visual lineal output signalrelated to a measured variable and for use with a transmitter whichproduces an output voltage signal the value of which is analogous to themeasured variable, said apparatus comprising an elongated dividerdefining a longitudinal series of lamp compartments, each compartmentbeing separated from the next successive compartment in said series by agenerally transversely extending partition, an electrically conductivestrip extending along one side of said divider and having a longitudinalseries of openings therein, each of said openings aligned with arespective one of said compartments, a longitudinal series of lamps,each of said lamps having a translucent envelope received in arespective one of said compartments and including a base received in arespective one of said openings, said base including two spaced-apartterminal portions, one of said terminal portions electrically contactingsaid conductive strip, an insulating strip extending along said oneside, and a longitudinal series of contacts mounted on said insulatingstrip, each of said contacts engaging the other of said terminalportions of a respective one of said lamps, and a plurality of lampcircuits, each of said lamp circuits being associated with one of saidlamps and including a control terminal and means for switching said onelamp from a deenergized to an energized state when the voltage on saidcontrol terminal exceeds a predetermined level and from an energized toa deenergized state when the voltage on said control terminal is lessthan said predetermined level, each of said lamp circuits beingresponsive to a different predetermined voltage level than the other ofsaid lamp circuits, said lamps being arranged to respond in longitudinalsequence to changes in said voltage level.
 2. An indicating apparatus asset forth in claim 1 wherein each of said lamp circuits includes meansfor adjusting said predetermined voltage.
 3. An indicating apparatus asset forth in claim 2 wherein said switching means includes afield-effect transistor, said control terminal comprises the gateterminal of said transistor and said adjusting means comprise means forvarying the voltage on the source terminal of said field-Effecttransistor.
 4. An indicating apparatus as set forth in claim 1 whereinsaid lamps include two groups of alternately arranged lamps, said seriesof compartments include two groups of alternately arranged compartmentseach of said openings along said one side aligned with a respective oneof said compartments in one of said groups and receiving the base of anassociated one of the lamps in one of said groups of lamps, anotherelectrically conductive strip extending along the other side of saiddivider and having another longitudinal series of openings therein, eachof said openings in said other series aligned with a respective one ofsaid compartments in the other of said groups and receiving the base ofan associated one of said lamps in the other of said groups, anotherinsulating strip, extending along said other side and anotherlongitudinal series of contacts mounted on said other insulating strip,each of said contacts in said other series engaging said other terminalportion of a respective one of said lamps in said other group.
 5. Anindicating apparatus as set forth in claim 1 wherein said insulatingstrip extends some distance rearwardly of said openings and the elementscomprising each of said lamp circuits are mounted on said insulatedstrip.
 6. An indicating apparatus as set forth in claim 5 wherein saidinsulated strip is a printed circuit board comprising a portion of eachof said lamp circuits.
 7. An indicating apparatus as set forth in claim1 wherein said conductive strip comprises a piece of electricallyconductive elastomeric material, and each of said openings beforereceiving the base of an associated one of said lamps is slightlysmaller than said base of said one lamp.
 8. An indicating apparatus asset forth in claim 1 wherein each of said compartments opens forwardlyand including a translucent plate adjacent the forward portion of saiddivider and covering said forwardly opening compartments.
 9. Anindicating apparatus as set forth in claim 1 wherein each of saidcontacts is mounted on said insulating strip for pivotal movementrelative thereto into and out of engagement with said other terminalportion of an associated one of said lamps, said one lamp beingremovable from said apparatus when the contact associated therewith ispivoted to a position out of engagement with said other terminal portionthereof.
 10. In indicating apparatus for providing a visual linealoutput signal related to a measured variable and for use with atransmitter which produces an output signal the value of which isanalogous to the measured variable, said apparatus comprising anelongated divider defining a longitudinal series of forwardly openinglamp compartments, each compartment in said series being separated fromthe next successive compartment in said series by a generallytransversely disposed partition, a strip of electrically conductiveelastomeric material positioned generally adjacent and extending alongone side of said divider and having a longitudinal series of openingstherein, each of said openings aligned with a respective one of saidcompartments, a longitudinal series of lamps, each of said lamps havinga translucent envelope received in a respective one of said compartmentsand including a base received in a respective one of said openings, saidbase including two terminal portions, one of said terminal portionselectrically contacting said electrically conductive strip, alongitudinally extending insulating strip overlying an associatedportion of said electrically conductive strip and extending rearwardlyfor some distance beyond said openings, a longitudinal series ofcontacts pivotally mounted on said insulating strip, each of saidcontacts being pivotally movable into and out of engagement with theother of said terminal portions of a respectively associated one of saidlamps, said one lamp being removable from said apparatus when thecontact associated therewith is pivoted to a position out of engagementwIth said other terminal portion thereof, a plurality of lamp circuits,each of said lamp circuits being associated with one of said lamps andincluding a plurality of circuit elements mounted on said insulatingstrip, each of said circuits having a portion thereof printed on saidinsulating strip and including a control terminal and means forswitching said one lamp from a deenergized to an energized state whenthe voltage on said control terminal exceeds a predetermined level andfrom an energized to a deenergized state when the voltage on saidcontrol terminal is less that said predetermined level, each of saidlamp circuits being responsive to a different predetermined voltagelevel than the other of said lamp circuits, said lamp circuits beingarranged to respond in longitudinal sequence to changes in said voltagelevel, each of said lamp circuits including means for adjusting saidpredetermined voltage, and a translucent plate adjacent the forwardportion of said divider and covering said forwardly openingcompartments. circuits , each of said lamp circuits being associatedwith one of said lamps and including a plurality of circuit elementsmounted on said insulating strip, each of said circuits having a portionthereof printed on said insulating strip and including a controlterminal and means for switching said one lamp from a deenergized to anenergzied state when the volatge on said control terminal exceeds apredetermined level and from an energized to a deenergized tate when thevoltage on said control terminal, is less that said predetermined level,each of said lamp circuits being responsive to a different predeterminedvoltage level than the other of said lamp circuits, said lamp circuitsbeing arranged to respond in longitudinal sequence to changes in saidvoltage level, each of said lamp circuits including means for adjustingsaid predetermined voltage, and a translucent plate adjacent the forwardportion of said divider and ocvering said forwardly openingcompartments.